A pointing device is an apparatus that a user manipulates in order to interact with a computer. The manipulation of the device is translated into movement of a cursor or pointer on a display screen of a computer, and interactive elements are provided on the pointing device for the input of various commands. Pointing devices include track balls, touch pads and joysticks, however, by far the most popular pointing device for use in a computing environment is the “mouse.” A computer mouse is moved over a mousing surface, the movement being translated into commands sent to a computer to move a displayed cursor or pointer in correspondence with the movement.
There are various technologies for encoding the movement of the mouse. One technology is the use of a track ball, together with rollers and encoders, so that physical motion of the track ball in the mouse rotates the rollers and outputs an encoded signal representative of the motion.
Recently, optical mice have become popular. An optical mouse comprises an illumination source within the body of the mouse, together with an image sensor. The illumination source shines onto a mousing surface and the image sensor is arranged to receive light reflected from the surface. Image processing software detects differences in successive frames of images collected by the image sensor and uses these differences to construct a motion signal to send to the computer for moving the cursor or pointer in correspondence with the motion of the mouse. The illumination source typically comprises a light emitting diode (LED), however it may also include an infrared laser diode or other suitable illumination means.
A computer mouse can communicate with a computer either through a wired or a wireless connection. Early wired connections use RS-232C or PS/2 connections while later wired mice tend to use a USB connector. Various other communication protocols are known and can be used for connecting a wired mouse to a computer. Wireless mice transmit their data via a radio frequency link to the computer. In most cases a radio frequency receiver is provided in a dongle which connects to a computer, typically via its USB port. This receiver then, detects the signals transmitted by a transmitter within the body of the mouse. In some cases the wireless receiver can be incorporated within the body of the computer. One example type of radio frequency communication that can be employed is bluetooth. A computer will normally have the components of the bluetooth stack within its body, although a separate bluetooth dongle can be provided.
Laptop computers are provided typically with touch pad pointing devices, however these can be cumbersome to use, and people may still prefer to use a stand alone mouse. However, for the business traveller it may be inconvenient to carry an additional device, particularly if that device requires an additional receiver or has a messy cable. The additional receiver can be dispensed with if the mouse has a bluetooth transmitter and if the laptop is provided with an integrated bluetooth receiver, however, adding the bluetooth functionality to a mouse can significantly increase the cost of the mouse as the bluetooth protocol is relatively complex compared with the standard mousing circuitry.
A mobile communication device in the context of this disclosure refers to any portable device that has a communications capability, for example a mobile telephone, personal digital assistant or equivalent. The present discussion will focus mainly on mobile telephones, although it will be appreciated that throughout the description references to mobile telephones could equally refer to any other type of mobile communications device.
Mobile telephones are provided with navigation pads for manipulating the focus of a cursor or a pointer on the display screen of a mobile telephone. Navigation pads in early mobile telephones comprise directional buttons or paddles for movement of a cursor in right, left, up and down directions.
Various mobile telephones are also available with a trackball navigation pad. A trackball uses mechanical encoders to translate the motion of the ball into motion of the cursor or pointer on the display screen of the mobile device.
Mobile telephones can also be provided with touch pads which translate the motion of a finger over the pad into motion of a cursor on screen. One type of touch pad is a capacitive touch pad, which uses the connection to ground caused by the contact of a finger with the pad as a means of determining a position of the finger. It is also known to provide touch pads that work using optical methods. These optical touch pads are known colloquially as finger mice. As for an optical computer mouse, an illumination source is provided and an image sensor are provided. In a finger mouse, the illumination source shines upwards from the body of the mobile telephone onto an underside surface of the touch pad. The image sensor detects light reflected from the underside of the touch pad. As a finger is moved over the touch pad image analysis is carried out to detect motion and translate that to movement of a cursor or a point on the display screen of the mobile device.
The image analysis could detect the relative position of a finger as it moves across the pad, or it could detect the relative position of ridges of skin of the finger as it moves, or of features of other items, for example a glove.
A business traveller may typically carry a laptop computer as well as a mobile telephone. They are then faced with the problem of carrying an extra device if they wish to use a pointing device for the laptop other than the touchpad which is provided. This is inconvenient and troublesome.